Sharpening tool



April 6, 1954 C. H. LOHMANN SHARPENING TOOL Filed Nov.

IN VEN TOR. CARL H. LOHMANN BY Patented Apr. 6, 1954 UNITED STATES PATENT OFFICE SHARPENING TOOL Carl H. Lohmann, Bronx, N. Y.

Application November 21, 1951, Serial No. 257,543

8 Claims.- (Cl. 51-211) This invention relates to new and useful improvements in sharpening tools.

More specifically, the present invention proposes the construction of a sharpening tool designed especially for sharpening blades of knives and the like which is characterized by a handle from which a pair of arms diverge and upon which sharpening members are mounted in a manner to sharpen and/or hone the edge of a blade drawn across the sharpening members.

Still further, the present invention proposes mounting the sharpening members to be exposed on the inner faces of th diverging arms in a manner so that the two sides of the knife edge can be sharpened by drawing one edge over one of th sharpening members and then drawing the other edge over the other of the sharpening members.

Another object of the present invention proposes characterizing the sharpening members by elongated abrasive stones removably mounted on the inner faces of the diverging arms in a manner to be interchanged with other stones of different coarseness or to be replaced when they have been worn away.

As a further object, the present invention proposes characterizing the sharpening members by sleeves of emery cloth or the like mounted in position on both of the diverged arms to have areas exposed completely about the circumference of the arms to be used for different types of sharpening and/or polishing purposes.

The present invention further proposes characterizing the sharpening members by elongated cylindrical stones formed as composite members to have sharpening surfaces of different grades of coarseness and rotatively mounted on th diverged arms in a manner to be turned to expose the sharpenin surfaces of th desired coarseness in sharpening position.

A further object of the present invention proposes removably mounting the cylindrical sharpening stones on the diverged arms of the tool so that they may be completely removed for replacement when desired.

It is a further object of the present invention to construct a sharpening tool of the type described which is simple and durable, which is effective for its intended purposes and which can be manufactured and sold at a reasonable cost.

For further comprehension of the invention, and of the objects and advantages thereof, reference will be had to the following description and accompanying drawings, and to the appended Fig. 3 is a view similar to Fig. 1, but illustrating a modification of the present invention.

Fig. 4 is an enlarged transverse sectional view taken on the line 44 of Fig. 3.

Fig. 5 is another view similar to Fig. -1, but illustrating a further modification of the present invention.

Fi 6 is an enlarged detailed sectional view ofthe outer end of one of the arms of the tool shown in Fig. 5.

Fig. 7 is an enlarged transverse sectional view taken on the line 1-1 of Fig. 5. V v

The sharpening tool, according to the first form of the present invention shown in Figs. 1 and 2, includes a handle H3 from one end of which a pair of arms H diverge. The handle 10 and the arms H are integrally formed of metal or similar material; however, if desired, those parts could be made of wood or one of the synthetic resinous materials without departing fro the scope of the present invention.

The inner faces of the arms 'I I are formed with grooves l5 which are dove-tailed in cross-sectionso as to snugly fit the dove-tailed projections I 4': The grooves l5 open to the outer' of the arms. ends of the arms H so that the sharpening members l2 can be pulled out of the outer ends of the rooves.

different grades of coarseness or for replacement when required. The dove-tailed projections M" of the sharpening members l2 have a tight frlc'-' tional fit in the complementary dove-tailed grooves 15 of the arms I! so that thes'harpen-fing members will maintain their positions on the see particularly.

The arrangement permits the removalf of the sharpening members l2 so that they may be interchanged with sharpening members or 3 arms Ii until such time as they are manually pulled from engagement with the grooves l5.

The construction provides a novel sharpening tool for sharpening and/or honing the edges of knife blades and the like, wherein the edge of the blade can be first drawn over the surface of one sharpening member i2 and then over the surface of the opposed sharpening member I2. Thus, the two sides of the knife blade can be sharpened and/ or honed at the same time without having to turn the knife in the hand or having to draw the blade along opposite sides of a single sharpening member.

In the modification of the invention shown in Figs. 3 and. 4, the sharpening tool is characterized by a handle 20 from which a pair of arms 2! diverge. tion, the arms 2! are integrally formed with the handle 20 and, as best seen in Fig. 4, each of the arms is circular in cross-section.

Each of the arms 2! has a sharpening member 22 mounted thereon. The sharpening members 22 in this form of the invention comprise sleeves of emery cloth or other similar abrasive material. The sleeves of emery cloth are mounted in position on the arms 2| by means of a layer of mucilage 23 having an amnity for both the material of the arms 2| and the backing material of the emery cloth.

The use of emery cloth as the sharpening members 22 in sleeve form, completely surrounding the arms 2| of the tool, provides surfaces on all sides of the arms which can be used for various sharpening and/ or cleaning purposes.

The form of the invention illustrated in Figs. to 7, is again characterized by a handle 38 from which a pair of arms 3! diverge. Upon each of the arms 31 there is mounted a sharpening member 32. As in the previous forms of the invention, the arms 3! are integral with the handle 30; however, the arms 3| distinguish in that they are in outline form to have spaced side portions 33 joined at their outer ends by cross portions 3 -1. The outer-most side portions 33 of the arms 3! are integral with the handle 20 and the innermost side portions are joined together at their inner ends providing a V-shaped formation as shown in Fig. 5. The formation of the arms 32 gives them a degree or" resiliency for a purpose which will become clear as this specification proceeds.

The sharpening members 32 are of elongated cylindrical formation to be circular in cross-section, as shown in Fig. 7. As in the first form of the invention, each of the sharpening members 32 is formed of abrasive stone such as Carborundum or the like and each is subdivided, as indicated by the dot and dash lines A in Fig. 7, into segmental parts of different coarseness varying from fine to extra coarse. For example, the degrees of coarseness might be fine, medium, coarse and extra' coarse. Notwithstanding the segmental formation of the sharpening members 32 each is made as an integral piece, as is generally known in the art of abrasives.

The inner faces of the side portions 33 of the arms 3! are made concaved, as best shown in Fig. '7, with their radii corresponding to radii of the sharpening members 32. Thus, with the sharpening members 32 fitted between the side portions 33, the sharpening members will be rotatively retained in position to be turned to expose the segments of the desired coarseness between the side portions 33 of the arms 3| for use when required.

As in the previous form of the inven- Means is provided for remova-bly holding the sharpening members 32 in the desired rotative position between the side portions 33 of the arms 3!. That holding means is characterized by a stud 35 for each of the sharpening members 32 and which studs are formed intermediate of their ends with enlarged collars 36, see Fig. 6. The cross portions 34 of the arms 3|, concentric with the sharpening members 32, are formed with holes 31 of a diameter to pass both the studs 35 and the collars 33. The outer ends of the sharpening members 32, concentric with the holes 31, are formed with axially extended internally threaded recesses 33. The inner ends of the studs 35, inward of the collars 36, are formed with threads 39 which are engaged with the threads of the recesses 38 fixedly mounting the studs in position on the outer ends of the sharpening members. From Fig. 6, it is apparent that the outer ends of the threaded recesses 33 are enlarged to admit the collars 33 so that the outer faces of the collars 36 are flush with the outer ends of the sharpening members 32.

The outer ends of the studs 35 are formed with enlarged knurled knobs 63 by which a grip can be had upon the outer ends of the studs for tightening them into position within the threaded recesses 33. The studs 35 between the adjacent faces of the collars 36 and the knobs 40 are provided with threads 4!. Threaded onto the studs 33 between the collars 36 and the knobs 49, there are winged nuts 42 of a diameter greater than the diameter of the holes 3?. It is appreciated, of course, that the knobs 48 are separate pieces mounted in position on the outer ends of the studs 35 after winged nuts 62 have been threadedly engaged in position.

By holding the studs 35 by the knobs 40, the winged nuts 42 can be tightened against the outer faces of the cross portions 34 of the arms 3! drawing axially outward on the studs 35. That will cause the outer ends of the sharpening members 32 to be drawn into good frictional contact with the inner faces of the cross portions 34 to retain the sharpening members 32 in rotative positions with the selected segmental parts of the sharpening members exposed for use.

The manner of assembling the sharpening tool shown in Figs. 5 to 7 is as follows: First, the sharpening members 32 are snapped into position between the adjacent faces of the side portions 33 of the arms 3! with the threaded recesses 33 facing the holes 31. The resiliency of the arms 31 resulting from the outline formation thereof permits the sharpening members 32 to be snapped into position. The studs 35 are then gripped by the knurled knobs 33 and the inner portions carrying the threads 39 are threaded into the threaded recesses 38 of the sharpening members 32 until the collars 35 are seated solidly within the enlarged outer portions of the recesses. The studs 35 are then fixedly connected with the sharpening members 32 which then may be turned between the side portions 33 to expose the desired segmental parts thereof for use. Finally, the winged nuts 42 are tightened against the outer faces of the cross portions 34 to retain the sharpening members 32 in the desired axially rotated positions with relation to the arms 3|. The procedure just described is then reversed when it is desired to free the sharpening members 32 for removal from the arms 31.

While I have illustrated and described the preferred embodiments of my invention, it is to be understood that I do not limit myself to the precise constructions herein disclosed and the right is reserved to all" changes and modifications coming within the scope of the invention as defined in the appended claims.

Having thus described my invention, what I claim as new andi desire to secure by United States Letters Patent is:

1. A sharpening tool, comprising a handle, a pair of arms extended divergingly from one end of said handle, and sharpening members mounted on said arms, said arms being of outline form to have spaced side portions joined at their outer ends by cross-portions, said sharpening members comprising elongated cylindrical abrasive stones positioned between said side portions.

2. A sharpening tool, comprising a handle, a pair of arms extended divergingly from one end of said handle, andsharpening members mounted on said arms, said arms being of outline form to have spaced side portions joined at their outer ends by cross-portions, said sharpening members comprising elongated cylindrical abrasive stones positioned between said side portions, said abrasive being integrally formed to have segmental parts of difierent coarseness.

3. A sharpening tool, comprising a handle, a pair of arms extended divergingly from one end of said handle, and sharpening members mounted on said arms, said arms being of outline form to have spaced side portions joined at their outer ends by cross-portions, said sharpening members comprising elongated cylindrical abrasive stones positioned between said side portions, said abrasive being integrally formed to have segmental parts of different coarseness, and means rotatively retaining saidf-abrasive stones in position between said side portions.

4. A sharpening tool, comprising a handle, a pair of arms extended divergingly from one end of said handle, and sharpening members mounted on said arms, said arms being of outline form to have spaced side portions joined at their outer ends by cross-portions, said sharpening members comprising elongated cylindrical abrasive stones positioned between said side portions, said abrasive being integrallyzformed to have segmental parts of difierent coarseness, and means rotatively retaining said abrasive stones in position between said side portions, said rotative retaining means comprising concaved surfaces on the inner faces of said side portions concentric with said abrasive stones and in facial contact therewith. -51

5. A sharpeningjtool, comprising a handle, a pair of arms extended'divergingly from one end of said handle, and sharpening members mounted on said arms, saifdlarms being of outline form to have spaced side portions joined at their outer ends by cross-portions; said sharpening members comprising elongated cylindrical abrasive stones positioned between said side portions, said abrasive being integrally formed to have segmental parts of difierent coarseness, and means rotatively retaining said abrasive stones in position between said side portions, and means holding said abrasive stones in the desired rotative positions with selected segmental parts thereof exposed for use.

6. A sharpening tool, comprising a handle, a pair of arms extended divergingly from one end of said handle, and sharpening members mounted on said arms, said arms being of outline form to have spaced side portions joined at their outer ends by cross-portions, said sharpening members comprising elongated cylindrical abrasive stones positioned between said side portions, said abrasive being integrally formed to have segmental parts of different coarseness, and means rotatively retaining said abrasive stones in position between said side portions, and means holding said abrasive stones in the desired rotative positions with selected segmental parts thereof exposed for use, said holding means comprising studs extended from the outer ends of said abrasive stones and through holes formed in said cross-portions, and winged nuts threaded onto the outer ends of said studs to'be tightened against the outer faces of said cross-portions.

7. A sharpening tool, comprising a handle, a pair of arms extended divergingly from one end of said handle, and sharpening members mounted on said arms, said arms being of outline form to have spaced side portions joined at their outer ends by cross-portions, said sharpening members comprising elongated cylindrical abrasive stones positioned between said side portions, said abrasive being integrally formed to have segmental parts of different coarseness, and means rotatively retaining said abrasive stones in position between said side portions, and means holding said abrasive stones in the desired rotative positions with selected segmental parts thereof exposed for use, said holding means comprising studs extended from the outer ends of said abrasive stones and through holes formed in said cross-portions, and winged nuts threaded onto the outer ends of said studs to be tightened against the outer faces of said cross-portions, said studs having removable threaded connection with said abrasive stones.

8. A sharpening tool, comprising a handle, a pair of arms extended divergingly from one end of said handle, and sharpening members mounted on said arms, said arms being of outline form to have spaced side portions joined at their outer ends by cross-portions, said sharpening members comprising elongated cylindrical abrasive stones positioned between said side portions, said abrasive being integrally formed to have segmental parts of different coarseness, and means rotatably retaining said abrasive stones in position betweensaid side portions, and means holding said abrasive stones in the desired rotative positions with selected segmental parts thereof exposed for use, said holding means comprising studs extended from the outer ends of said abrasive stones and through holes formed in said cross-portions, and winged nuts threaded onto the 'outer""ends of said studs to be tightened References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,352,888 Gallagher Sept. 14, 1920 1,619,833 stegner Mar. 8, 1927 ,630,182 Jacobs May 24, 1927 39 Miller July 31, 1945 FOREIGN PATENTS Number Country Date 197,209 Switzerland Apr. 15, 1938 271,120 Switzerland Got. 15, 1950 

